Freezing batteries that already have a charge slows their rate of self-discharge, and slows the chemical reactions that slowly degrade all batteries.
Similarly, higher temperatures have the opposite effect on batteries, which is one of the reasons why laptop batteries tend lose capacity so quickly. (The other reason being that lithium-ion batteries trade off longevity for power density, as market demand trends much more towards batteries that have longer run-time than batteries that last decades.)
The calibration cycle, as mentioned by m_cowen_uk, may help to regain a small amount of capacity from your battery. Usually, though, the calibration cycle simply readjusts the point at which the battery is considered to be charged and discharged, to compensate for it's gradual loss of capacity.
That'll make Windows' automatic shutdown/hibernate/whatever function properly again, but freezing a battery isn't going to restore any of it's capacity.